What Benefits Do We Get From Coal Washing Machines?

 

 

What is coal cleaning?

Relying on its high quality, coal needs to be "cleaned" with water and also chemicals to remove sulfur and also contaminations prior to it can be melted in a power plant. Coal washing, or coal beneficiation, is widely seen as an efficient method for obtaining one of the most from run-of-mine coal. On the other hand, it is a water-intensive process: generally, washing one ton of coal consumes regarding 45 m3 liters of water. As environmental policies tighten up, mechanical mining raises pollutants in run-of-mine coal, and manufacturing rates continue to rise, there is a constant demand for improving coal top quality.

 

Why do you need a coal washing machine?

 

Today, coal provides a 3rd of all power made use of worldwide as well as composes 38% of electricity generation. Additionally, sectors such as iron & steel, cement, fertilizers, and also pulp & paper rely upon coal for their procedures as well as power needs. Given the position of coal in the worldwide power structure and the reputable ecological problems related to it, the production of clean coal technologies is vital to complete both efficient energy production as well as a reduced ecological footprint. This is where coal cleaning is available in.

 

Benefits of coal washing

1. The process of coal washing decreases carbon dioxide and also transforms them into a rich supply of residential power. This will certainly not only reduce the harmful emissions from burning coal but also convert it right into a rich supply of power.
2. Cheaper and far better alternative to natural gas and various other sorts of fuels as it is so affordable to establish a brand-new coal plant altogether. Coal is a more affordable and more generously discovered fossil fuel when contrasted to others. It is elder than other types of eco-friendly power plants, which allows making use of clean coal for residential objectives.
3. Clean coal can also be achieved by an approach of filtering. In this process, filters are installed on exhausts to catch the greenhouse gases when coal is melted. The gaseous discharges from melted coal are saved underground.

 

Coal Washing Process

 

Coal washing is completed by a couple of significant procedures, thickness splitting up or froth flotation. Both processes depend upon the reality that the particles of which a coal sample is made have different thickness. When water is added to the example, fragments sink to various depths relying on their densities. The numerous components of the example can be divided from each various other. A number of tools and systems have been created for extracting the numerous elements of coal once they have actually been divided with water therapy. Among these gadgets is the jig. In a jig, the column of water is maintained in a continuous up-and-down movement through a flow of air. Tidy coal fragments are carried to the top of the jig by this movement, while heavier refuse fragments sink to the bottom.

We are a coal cleaning machines supplier, please do not hesitate to contact us if you require them.

Why Should Coal Be Washed?

 

Coal Washing Machine

Why Should Coal Be Washed? Coal from coal mine is a complex material mixture with multiple physical properties. In addition to coal itself, this mixture also contains rocks, sand and various minerals. Therefore, coal must be cleaned before being sold to consumers. The cleaning process includes a series of steps, and finally produces products that are particularly suitable for specific consumer needs. The earliest of these steps is crushing and sorting. These two processes can reduce coal to the form required by consumers.

The coal washing plant has improved the coal washing process and quality, thereby increasing the price. Coal washing technology also helps reduce emissions from combustion.

 

How to wash coal?

There are two main coal preparation methods, one is density separation and the other is froth flotation. Both processes depend on the fact that the particles from which the coal sample is made have different densities. For example, when water is added to the sample, the particles will sink to different depths according to their density. In this way, the various components of the sample can be separated from each other.

Coal cleaning is a process by which impurities such as sulfur, ash, and rock are removed from coal to upgrade its value. Coal cleaning processes are categorized as either physical cleaning or chemical cleaning. Physical coal cleaning processes, the mechanical separation of coal from its contaminants using differences in density, are by far the major processes in use today. Chemical coal cleaning processes are currently being developed, but their performance and cost are undetermined at this time. Therefore, chemical processes are not included in this discussion.

The scheme used in physical coal cleaning processes varies among coal cleaning plants but can generally be divided into four basic phases: initial preparation, fine coal processing, coarse coal processing, and final preparation.

In the initial preparation phase of coal cleaning, the raw coal is unloaded, stored, conveyed, crushed, and classified by screening into coarse and fine coal fractions. The size fractions are then conveyed to their respective cleaning processes.

Fine coal processing and coarse coal processing use similar operations and equipment to separate the contaminants. The primary difference is the severity of operating parameters. The majority of coal cleaning processes use upward currents or pulses of a fluid such as water to fluidize a bed of crushed coal and impurities. The lighter coal particles rise and are removed from the top of the bed. The heavier impurities are removed from the bottom. Coal cleaned in the wet processes then must be dried in the final preparation processes.

Final preparation processes are used to remove moisture from coal, thereby reducing freezing problems and weight and raising the heating value. The first processing step is dewatering, in which a major portion of the water is removed by the use of screens, thickeners, and cyclones. The second step is normally thermal drying, achieved by any one of three dryer types: fluidized bed, flash, and multilouvered. In the fluidized bed dryer, the coal is suspended and dried above a perforated plate by rising hot gases. In the flash dryer, coal is fed into a stream of hot gases for instantaneous drying.

The dried coal and wet gases are both drawn up a drying column and into a cyclone for separation. In the multilouvered dryer, hot gases are passed through a falling curtain of coal, which is then raised by flights of a specially designed conveyor.

 

Purpose of coal washing equipment:

1. Reduce water and energy-intensive coal production

The coal washing program includes factory installation and independent modules to optimize beneficiation capacity. In other words, this means maximizing the ore recovery rate while using less water, energy or other consumables in the process.

Another important feature is water conservation. By enhancing water conservation, zero discharge of wastewater and reducing carbon emissions, this solution helps to achieve a more sustainable process.

2. A more sustainable process helps reduce operating costs

To meet the needs of customers for greater flexibility and efficiency in terms of sustainability. Our philosophy is to provide comprehensive solutions for the industry.

 

Structural characteristics of coal washer:

1. Standard length valve body can be used, and the combined shape can be selected according to needs.

2. Coal washing technology-the use of CNC pneumatic valve, high degree of automation of coal washing.

3. Coal preparation method-double-amplitude pulsed water flow, good bed stratification effect and high clean coal yield.

 

We are a coal washing equipment supplier. If you are interested in our products, please contact us now!

Benefits Of Vibrating Screens

 Vibrating screen is one of the main types of industrial screening equipment. There are several mechanical screening solutions in the solid waste management, recycling, and polymerization industries; however, vibrating screens provide many unique advantages that make them the first choice for various industrial applications.

Read on to learn more about how vibrating screens work and their benefits over other common types of screening equipment.

 

What is a vibrating screen?

As the name implies, the design of the vibrating screen is based on the principle of transmitting vibration to the screening surface in order to separate and classify different particles according to their size.

Regardless of the design of the machine, the principle is the same: vibration breaks the surface tension between particles, thereby forcing them to separate. Particles that are too small, so-called "fines", pass through the screen. At the same time, oversized particles are carried through the screen surface. This is an important application in many industries, especially mineral processing.

What are the benefits?

Due to its unique design features, the vibrating screen has special advantages over other material processing equipment, including:

• Improve processing and material quality

• Low operating cost

• Reduce maintenance and downtime

• High screening efficiency

 

Vibrating screen

We will explain these benefits in further detail below.

• Improve processing and material quality

Although certain screening equipment is more suitable for different materials, vibrating screens have many advantages in the processing of aggregates and mining materials. The equipment of the vibrating screen is particularly sophisticated to meet the fineness requirements of these industries. Their design can generate the force required to separate large particles from fines, thereby making the product easier to recycle—even when processing materials that require significantly smaller particle size separation. This leads to higher yields and an improvement in the overall quality of the final product.

• Low operating cost

The vibrating screen is famous for its sturdy design. Because the working principle is relatively simple, and the design of modern machines is streamlined, vibrating screens are generally bought less than other types of screens. This resulted in lower upfront investment.

In addition, compared with more complex machinery, the vibrating screen can run with lower energy consumption, thereby saving the company's continuous operating costs. Finally, because the high-frequency vibration is directly transmitted to the screen surface, only the media on the screen surface needs to be replaced regularly. This can help save the maintenance and repair costs that other screening equipment often constitutes.

• Reduce maintenance and downtime

Maintenance and downtime caused by repairs or equipment failures can result in significant losses in productivity and profits. Many types of screens have experienced severe wear, especially in demanding applications such as aggregate processing. However, the vibrating screen offers the advantage of less maintenance and downtime. This is the result of their design, the center of which is to only transmit the exciting force to the screening surface.

In addition, high-quality vibrating screening equipment is designed and manufactured to minimize the impact of other parts of the machine by the exciting force. In more complex designs, the structure of the machine allows sufficient absorption and suppression of vibrations other than the screen media. This results in fewer moving parts and less wear, further reducing downtime and maintenance.

• High screening efficiency

Although there are various screening equipment on the market, when a simple solution is needed that can handle higher feed flow rates, vibrating screens provide an ideal choice. In fact, the vibrating screen has the highest working efficiency and the flow rate is always higher. For other types of screening equipment, the same material throughput may result in blind screening or material backflow, requiring a slower feed.

We are vibrating screen suppliers. Please feel free to contact us if you are interested in our products.

Coal Washing Machine: What Is Coal Washing?

 

 

Today, coal supplies a third of all energy used worldwide and makes up 38% of electricity generation. In addition, industries such as iron & steel, cement, fertilizers, and pulp & paper rely on coal for their processes and energy requirements. Given the position of coal in the global energy framework and the legitimate environmental concerns related to it, the production of clean coal technologies is essential to accomplish both efficient energy production and a reduced environmental footprint. This is where coal washing comes in.

 

Depending on its quality, coal needs to be “washed” with water and chemicals to remove sulfur and impurities before it can be burned in a power plant. Coal washing, or coal beneficiation, is widely seen as an efficient method for getting the most from run-of-mine coal. On the other hand, it is a water-intensive process: typically, washing one ton of coal consumes about 45 m3 liters of water. As environmental regulations tighten, mechanized mining increases impurities in run-of-mine coal and production rates continue to surge, there is a constant need for improving coal quality.

 

A coal preparation plant is a facility that washes coal of soil and rock, crushes it into graded size chunks and stockpiles grades, preparing it for transport to market. Coal washing represents the most important step of coal preparation. The raw run-of-mine coal requires selective qualitative and quantitative analysis for finding the most suitable operating conditions for cleaning coal to obtain the desired quality. Among these analyses, the washability test is most important.

 

Coal that comes from a mine is a complex mixture of materials with a large variety of physical properties. In addition to the coal itself, pieces of rock, sand and various materials are contained in the mixture. Thus, before coal can be sold to consumers, it must be cleaned. Coal washing involves using water and mechanical techniques and relies on gravity and the difference of density between coal and its’ impurities, which are usually more densely packed due to the fact that they are inorganic. Washing coal increases its efficiency and quality, therefore increasing its price. Coal washing can also help to reduce emissions from burning.

 

The washability characteristics of a coal reserve are provided by obtaining liberation data on the raw coal sample. Liberation refers to the amount of physical breakage required to separate material of different material densities. Low density material is clean coal while high density material is reject rock.

 

Coal washing is accomplished by one of two major processes, by density separation or by froth flotation. Both processes depend on the fact that the particles of which a coal sample are made have different densities. When water is added to the sample, particles sink to various depths depending on their densities. The various components of the sample can be separated from each other. A number of devices and systems have been developed for extracting the various components of coal once they have been separated with a water treatment. One of these devices is the jig. In a jig, the column of water is maintained in a constant up-and-down movement by means of a flow of air. Clean coal particles are carried to the top of the jig by this motion, while heavier refuse particles sink to the bottom.

 

In the coal washing process, the washability characteristics of coal are applied:

• To find the relative ease for separation of coal from the refuse.

• To find the effectiveness of coal washing.

• To characterize the type and amount of impurities.

• To gather the information for designing a separation plant.

The washability test is done by float and sink method. It is an important analytical technique for the cleaning of coal in the most effective way.

 

We are a Coal Washing Machine supplier. If you are interested in our products, please contact us now!

Application Guide for Slurry Pumps – How To Use Slurry Pumps Efficiently

Slurry pumps are dominantly popular for their robust construction and the ability to work under strenuous situations. The process industry mainly works with centrifugal pumps and the ratio between slurry and other pumps for liquid is nearly 5:95. But if you take a look at the operating costs for these pumps, the ratio turns nearly upside down with 80:20 which explains the wide popularity of slurry pumps.

 

 

Introduction To Slurry Pumps

A slurry pump is a unique type of a pump which is used to handle slurry. Contrary to water pumps, slurry pumps are heavy-duty constructed and undergo more wear and tear. Technically, slurry pumps are a heavy and robust version of centrifugal pumps that have the capability of handling abrasive and tough tasks. As compared to other pumps, slurry pumps have a much simpler design and construction. Despite an elementary design, slurry pumps offer high endurance and strength under harsh conditions. These forms of pumps play a crucial role in various industries. They are fundamental to all wet processes.

What is Slurry?

In principle, it is possible to hydro transport any solid. Particle size and shape, however, may act as limiting factors based on whether they can pass through pump tubes without creating blockages. Under the broad category of slurry, there are 4 major classifications that can help you identify a suitable type of slurry pump that fulfills your demands and meets your business requirements.

• Type 1:Mildly Abrasive

• Type 2:Slightly Abrasive

• Type 3:Significantly More Abrasive

• Type 4:Highly Abrasive
If you want to move highly abrasive type 4 slurries, the ideal choice would be Oil sand pumps. The ability to handle high volumes of slurry and the enhanced withstanding capability is what gives an edge to slurry pumps. They are specifically designed to hydrotransport large-particle solids and ensure better wear performance in rough conditions.

 

Four centrifugal slurry pump types

Although centrifugal slurry pumps are widely known for their uses in oil sands, many of them have additional uses as well.
• Hydrotransport— Hydrotransport pumps are used for plenty of applications because moving slurry is hydrotransport. The ideal way to use these slurry pumps is with water-based solutions. They are mostly used in industries which require dredging.
• Tailings Transfer— Tailings Transfer pumps are the perfect type of pumps to transport tailings or finer abrasive materials resulting from hard rock mining, such as fragments of mud and ore, as well as related chemicals used in the mining process.
• Cyclone Feed— Cyclone feed pumps, like tailings pumps, are also used in hard rock mining and are comparable to hydrotransport pumps as they are also used in dredging operations. These forms of pumps are used at all stages of scalping and separating solids by particle size.
• Flotation Froth— A slurry pump can also be used for transporting froth, however the air trapped in the froth can negatively impact the pump’s performance. Even though slurry pumps are built with a sturdy construction, the air contained in the froth can damage the pump and shorten its life. But, with proper preventive measures of centrifugal pumps, you can reduce the wear and tear of the pump.

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Working principle

Slurry pumps have a simple and robust construction. The working principle of a slurry pump is relatively much simpler and easier to follow than other pumps.
The slurry enters the pump through the rotating impeller which imparts a circular motion. The slurry is then pushed outwards by the centrifugal force and moves between the blades of the impeller. The slurry picks up speed by the time it hits the impeller’s edge. Its high-speed energy is converted into pressure energy in the casing.
With the assistance of centrifugal force, the pumps boost the pressure of a liquid and solid particles transforming the electrical energy to kinetic energy to pump the slurry. This system allows pumping of light slurry liquids easily without much hassle and keeps it maintenance free.

Benefits of Slurry Pump for Industrial applications

• Easy maintenance

• Low capital costs

• Simple mechanism

• Robust machinery

• Stainless steel material to reduce wear and tear

 

 

Selection of Slurry Pump

The selection of the right pumps for specific slurries can help pump owners avoid unnecessary repairs, maintenance, related downtime and wear of the machinery. In addition to this, proper pump selection and application helps create a safer work environment for employees, ensuring a secured workplace where they can work easily without worrying about life threatening conditions in case of an improper installation. The best slurry pumps to choose for your business is the one that serves your purpose. Choosing a slurry pump depends on many factors. While selecting a slurry pump for your company, you have to analyse pump curves to identify the best option. One of the most important things to remember while selecting a slurry pump is to make sure to choose a pump that can operate as slowly as possible to reduce wear, bust fast enough to move the slurry through it efficiently without settling or clogging in the pipes. Given that these pumps have high endurance and longer wear lives, they can be used across different industries for a wide range of purposes. The most used method for selection of slurry pumps is to calculate the Total Dynamic Head for the particular application: Total Dynamic Head = Head due to friction loses + Static Head – Head due to submergence

If you are still confused about which pump to choose for your business goals, feel free to reach out to us at sales. With experience of working with centrifugal pumps in the industry and a team of professionals on board, we help businesses design and implement their strategic goals. Right from identifying the ideal pump for your company, to installing it, running regular performance checks, evaluating its efficiency levels for detection of faulty components, and helping with as simple or as complex issues, we will help you do it all.

 

Metallic & Industrial Minerals

► Pumps for grinding circuits

For particles with size below 5mm, it is recommended to use a rubber slurry pump. If possible, mix flows that contain fine and coarse particles together for enhanced stability of the slurry.

• Pumps for froth

This range is specially built for froth pumping. Slurry pumps that are used for froth pumping often undergo severe abrasion and damage caused due to the air trapped in the froth, but we ensure that proper preventive measures are taken to avoid any faulty elements or decreased output efficiency.

• Pumps for tailing

Depending on the particle size of the slurry, both metal and rubber pumps can be used for tailing. To know more about how to choose an ideal slurry pump for your organization, you can talk to our professionals who can carry out an on-site inspection, note down all your requirements and help you in choosing the right pump for your business needs.

• Pumps for pressure filter feed

Choose a high head pump with variable speed control for pressure filter feed. Avoid using rubber due to the low flow head build up.
Pumps for tube press feedMetal pumps are more suitable for tube press feed as they have a high head with small flow. One slurry pumps can feed multiple tubes using a slurry distribution ring.

• Vertical and Horizontal Slurry Pumps for hydrocyclone feed

Tank pumps are considered as dry installed pumps, they are a kind of vertical slurry pumps that can be effectively used for dewatering cyclones. For a sharp classification, you can use horizontal slurry pumps which are often called as dry mounted because the drive unit and the hydraulic end are located outside the sump.

• Pumps for floor sumps

Slurry pumps can also be used for floor sumps. Make sure to use pumps with metallic wear parts, as there is often a risk for oversized tramp material coming into floor sumps. However, if rubber must be used, put a strainer either in front of the pump or around the pump.

► Construction

• Pumps for wash water (sand and gravel)

Usually, vertical pumps are more preferable for wash water but you can also use horizontal pumps of a suitable range that serves your purpose.

• Pumps for sand transportation

Slurry pumps are heavily used for sand transportation. The ideal choice is mostly horizontal pumps with rubber lining.

• Pumps for tunnel dewatering

Since the front pumps use drainage pumps, the best choice for the initial transportation stage is vertical pumps. But, the selection of a slurry pump for tunnel dewatering depends on multiple factors such as cuttings from full-face boring, horizontal distant pumping, small tunnels, etc.

► Power & FGD

• Pumps for FGD reactor feed (lime)
You can use slurry pumps with either rubber and/or metal parts. They perform extremely well in FGD reactor feeds.

• Bottom ash pumping

Because of the high temperatures involved, metal slurry pumps are preferred over rubber pumps. The sturdy built of the pumps allows it to withstand strong temperatures with minimal damage and abrasion.

• Fly ash pumping

There are high chances of oil contamination in the process of ash pumping. Metal slurry pumps are used over rubber for this application as they lower the risk of oil contamination. However, if rubber must be used, look for any other oil or chemicals that are not reactive with rubber.

 

► Waste and Recycling

• Pumps for effluent handling
Go for metal pumps for effluent handling of the waste and recycling materials. You can use either vertical or horizontal slurry pumps, as per your needs.
• Hydraulic transportation of light waste
Prefer using horizontal slurry pumps with vortex-induced flow impellers.
• Pumps for soil treatment
Slurry pumps are highly efficient in soil treatment. Owing to their robust construction, they can withstand extreme temperatures and rough climate change as well.

► Chemical

• Pumps for acid slurries

The ideal suggestion of slurry pumps for dealing with acid slurries is horizontal pumps with rubber or stainless steel.

• Pumps for brines

Brines are usually highly abrasive and can potentially damage pumps, this is why slurry pumps are the best option to choose when working with brines. Substances like polyurethane can be used to prevent crystallization on the pump parts.

• Pumps for caustics

Both rubber and metal slurry pumps can be used for working with caustics as it is an easy and light application.

► Mining

• Pumps for hydraulic backfilling

Keep a close watch for any deslimed tailings. You can use metal slurry pumps with metal or rubber parts for hydraulic back filing with or without cement.

• Pumps for mine water (with solids)

For mine water, use horizontal slurry pumps. Make sure you take preventive measures to avoid corrosion in the slurry pump as it can reduce the efficiency of the pump and damage its components.
 

► Pulp & Paper

vPumps for liquors

Slurry pumps are well suitable for liquors, however, rubber is not recommended due to the risk of turpentine.

• Pumps for lime and caustic mud

Working with lime and caustic mud involves high temperatures which can be tolerated by slurry pumps. Since the temperatures are high, it is recommended to use metal slurry pumps instead of rubber.

• Pumps for reject pulp (containing sand)

Usually, this requires light duty pumps, but it is advised to use metal slurry pumps that can handle heavy flow and provide strong support to the slurry passing through it.

• Pumps for solids from debarking

Use metal slurry pumps with induced flow impeller for sand and bark as they have the potential to cause heavy abrasion.

• Pumps for hydraulic transportation of wood chips

The best option to use for hydraulic transportation of wood chips is induced flow pumps.

• Pumps for paper filler and coating slurry

Avoid using rubber pumps as they can cause color contamination which can affect the entire production. Instead, go for metal slurry pumps that can be easily used for paper filler and coating slurry.

 

Takeaway

Slurry pumps are widely popular pumps that are used for handling robust and difficult tasks as they have sturdy construction. They can work efficiently in harsh conditions and are widely used across different industries for plenty of applications. Slurry Pumps can be used in the following industries:

• Metallic & Industrial Minerals

• Construction

• Power & FGD

• Waste and Recycling

• Chemical

• Mining

• Pulp & Paper

If you want to know more about how to select the best centrifugal pump for your business needs or need an extra hand with the maintenance of your pumps, Fengwang is here to help you.

Slurry Pumps VS. Water Pumps: Why Do I Need A Slurry Pump?

 

 

When it comes to slurry transportation, familiarity with pumps and their parts is par for the course. However, it's also important to understand what goes into each element of slurry transport. That understanding starts with a few basic questions: “What's the difference between a slurry pump and a water pump?” “What makes a slurry pump special?” and “What kinds of slurry pump installations are there?”

 

Slurry pumps versus water pumps

What distinguishes slurry from other fluid types is the presence of a solid — gravel, copper, or sand — within a liquid. Although, in many cases, that liquid is water, a slurry may contain solvents, like acids, alcohols, or petroleum. Those non-water components, whether solids or solvents, make slurry pumps necessary.

slurry-types

In contrast to water pumps' narrow and often inexpensive components, large replaceable slurry pump parts are made of sturdy, often specialized materials. These parts allow pumps to move nearly any type of solid within a slurry efficiently and safely. Water pumps, on the other hand, lack the hydraulic capacity to move solid particles and are unable to withstand the particle abrasion and chemical corrosion that slurries can cause.

 

What makes slurry pumps special?

Slurry pumps can withstand extensive wear due to characteristics such as: a large impeller diameter, shafts, bearings, and internal passageways as well as heavy-duty construction. On an industrial level, slurry pump features generate higher upfront and operational costs compared to water pumps. However, only slurry pumps can hydrotransport solid materials efficiently, and the long-term benefits outweigh initial costs.

Centrifugal force pushes something outward when it's spinning rapidly around a center.

Key to slurry pump success is the generation of centrifugal force, which pushes material outward from the pump center. This contrasts with centripetal force, which pushes material toward the center. Slurry pumps must operate on centrifugal principles because the forces that impart velocity to the slurry accelerate the transport process. A centripetal pump, on the other hand, would be impractical since the solids within the slurry would accumulate instead of flowing freely.

 

Slurry pump installations

Knowing these basics, it's also important for anyone looking to install a slurry pump to understand the specific environments required for each type of pump. Three types of slurry installations exist:

Wet — In this installation, the slurry pump and drive are fully submersible. This is necessary for certain slurry pump applications, such as underwater operations.

Dry — In this installation, the pump drive and bearings are kept out of the slurry. The wet end — which includes the shell, impeller, hub or suction liner, and shaft sleeve or stuffing box — is free-standing and clear of any surrounding liquid. Slurry pump technicians install most horizontal pumps this way.

Semi-dry — This special arrangement is used for dredging applications with horizontal pumps. Operators flood the wet end and bearings but keep the drive dry. Bearings require special sealing arrangements in this case.

Although this guide provides an overview of slurry pumps and their installations, there's plenty more to learn. For those who want to better understand slurry pumps and their applications or need help deciding which pump and installation type is best for their applications, Fengwang is here to help.

Filter Press Basics

 

 

The Filter Press is one of the oldest filtration technologies still in use today. It was first developed in the mid 1800's. Unlike vacuum filters, which operate continually, the Filter Press and many other pressure filters run in batches. After a batch of slurry has run through the filter, and the filtrate drained out, it must shut down, open the filter pack, and discharge the solid cake.

The components of a filter press include the frame or skeleton and the filter pack. The filter pack consists of plates, sometimes frames, and filter media.

 

Frame Components

Stationary Head- The side of the frame without the closure system has a head that aligns with the filter pack. It is also known as the fixed head. It has a feed hole for the slurry to enter and drain hole for filtrate to exit.

Follower Head- The hydraulic ram pushes the follower head, or thrust head against the filter pack. There are no feed or drain holes on this head.

Closure System- A hydraulic ram is used to press the plates together and hold the filter together during operation. It creates a positive seal and prevents leaks.

Sidebars- The filter press plates rest on sidebars to keep alignment and bear weight.

Pump- Necessary to create the pressure which drives the process, it is usually a positive displacement pump or a centrifugal feed pump.

Extra Features- Newer models can include additional components like plate shifters, spray bars, and automatic cake dischargers.

 

Types of Plates

Plate and Frame Filters- Plate and Frame was the original design, and is still used in some applications. The plate has a series of channels or pips creating high and low points. A cloth or paper filter media sits on top of the plate and filtrate passes through in the drainage area around the low points. The frame creates the empty space necessary for two plates to have a chamber between them. Cake accumulates within the chamber.

Recessed Filter Plates- Recessed filter plates eliminate the need for frames. The plate's border is thicker than the high points of the drainage area, creating half of the chamber. The plate it touches creates the other half.

CGR: Caulked Gasketed Recessed Filter Plates- CGR plates are a recessed plate that has filter media caulked into place, normally in an octagonal configuration. It seal feed and drain holes with o-rings.

Diaphragm Filter Plates- A recessed filter plate with a diaphragm. When solid cake has bridged its chamber, touching both plates, water is pumped into the diaphragm which swells. This swelling decreases the amount of space available, further dewatering the cake. Diaphragm plates are sometimes staggered with recessed filter plates, so that only one side of any given chamber will swell.

 

Industrial Filter Media

While cotton was the main filter media, in the 1960's synthetic fibers created better performing and longer lasting press cloths. National Filter Media  has a wide variety of fibers, and weave types.

Here is a list of configurations for Media.

Drape over cloth- Twice the length of a plate, a Drape Over Cloth sits on top of the plate and lays down each side. It can be held in place by small nubs, or “dog ears”.

Drape over paper- If cake has a tendency to blind filter media after one batch, a filter paper can be draped on top of the cloth. When the Filter Press opens to discharge, the paper is thrown out with the cake.

Duplex cloth- Two separate cloths, each the size of a plate's single face, are sewn to a gusset that covers the feed hole that runs through a plate. The top and side edges of the cloth either have grommets or Velcro to secure both side of the cloth to the plate.

CGR Cloth- This duplex cloth is shaped to fit in the groove of a CGR Plate. There is a rope sewn into the cloth's border that gets caulked into each side of the plate.

 

We are a Filter Press supplier. Please feel free to contact us if you need them!